Final answer:
The nurse would explain that a cancer patient's need for higher doses of opioids, like morphine, is due to the development of tolerance over time, not necessarily indicative of addiction or a high risk of overdose.
Step-by-step explanation:
The nurse would educate the mother about the concept of tolerance to opioids. As a cancer patient's body becomes more tolerant to the effects of opioids like morphine, higher doses may be required to control pain effectively. This is a common situation in cancer pain management and does not necessarily equate to addiction or carry a direct risk of overdose when managed carefully by a medical professional. It's essential to understand that there is no absolute maximum opioid dose because each patient's pain management needs and tolerance levels are unique. The medical team will continually assess the patient's response to the drug and the pain levels to adjust the dosage as needed, always considering the patient's safety.